In conventional cloud computing, users can use the resources of the cloud system. Particularly, users can store and access the data in the cloud system; moreover, users can even use the applications deployed at the cloud system end and retrieve the results only. Accordingly, the storage and the computing resource at the user end can be saved efficiently. However, in the existed cloud computing structures, the resources user can use at a time are almost limited in one cloud system.
Further speaking, in the current cloud computing structures, once a user connects to a cloud system, the user can use only the resources of the cloud system. Therefore, since each cloud system works independently, the user's on-going works on one cloud system will be failed directly if the cloud system crashes. In other words, the user's work can not be processed through different cloud systems since each cloud system works independently. Accordingly, the uses of the current cloud systems will be very inflexible and limited.
Hence, an urgent need exists in the art to integrate the different cloud systems for increasing the availability and the flexibility of cloud computing.